wordmodel: honor explicit underline off values

crates/wordmodel/src/props.rs

@@ -93,6 +93,16 @@ mod tests {
         }
     }
 
+    #[test]
+    fn explicit_off_values_disable_underline() {
+        for value in ["off", "false", "0"] {
+            assert_eq!(Underline::from_ooxml(value), Underline::None, "{value}");
+        }
+        assert_eq!(Underline::from_ooxml("none"), Underline::None);
+        assert_eq!(Underline::from_ooxml("single"), Underline::Single);
+        assert_eq!(Underline::from_ooxml("unknown"), Underline::Single);
+    }
+
     /// The 16 `w14:ligatures` values of [MS-DOCX], each to its flags and back.
     #[test]
     fn ligature_names() {

crates/wordmodel/src/props/char_props.rs

@@ -51,6 +51,10 @@ impl Underline {
     }
     pub fn from_ooxml(s: &str) -> Underline {
         Underline::ALL.iter().copied().find(|u| u.ooxml() == s).unwrap_or(match s {
+            // Some Word producers serialize the generic on/off values here, although the
+            // underline simple type normally uses `none`. Honor an explicit disable rather
+            // than treating an unrecognized value as the default single underline.
+            "off" | "false" | "0" => Underline::None,
             "thickDash" | "dashLong" | "dashedHeavy" | "dashLongHeavy" => Underline::Dash,
             "dottedHeavy" => Underline::Dotted,
             "wavyHeavy" => Underline::Wave,